Butler, J. D. (1957). Four philosophies and their practice in education and religion (Rev. ed.). Harper.
Lua i Stíl Chicago (17ú heag.)Butler, James Donald. Four Philosophies and Their Practice in Education and Religion. Rev. ed. New York: Harper, 1957.
Lua MLA (9ú heag.)Butler, James Donald. Four Philosophies and Their Practice in Education and Religion. Rev. ed. Harper, 1957.
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